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You searched for: creator:"LETICIA"
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Downloads: 27
Downloads: 24
[texts]On the ku-homology of certain classifying spaces II - Leticia Zarate
We calculate the annihilator of the ku-toral class for the p-groups Z_{p^2} X Z_{p^k}$ with k > 2. This allows us to give a description of the ku-homology of these groups.
Downloads: 3
[audio]Grito de Asencio - Leticia Tenjido
Canci{on sobre la lucha de 1811, el Grito de Asencio. Mercedes -Soriano
Keywords: grito; asencio; batalla; orientales; uruguay
Downloads: 10
[audio]Tp 3: Vivir en los Márgenes - Maria leticia
Keywords: VIVIR
Downloads: 17
[audio]tp numero 3 - maria leticia
Keywords: ley de talles
Downloads: 10
[audio]Le Soleil - Leticia Frenette
Original Song
Keywords: song; original
Downloads: 5
[texts]On the ku-homology of certain classifying spaces - Leticia Zarate
We calculate the ku-homology of the groups Z/p^n X Z/p and Z/p^2 X Z/p^2. We prove that for this kind of groups the ku-homology contains all the complex bordism information. We construct a set of generators of the annihilator of the ku-toral class. These elements also generates the annihilator of the BP-toral class.
Downloads: 3
[texts]Enrichment of the Intergalactic Medium by the Milky Way Subgroup - Leticia Carigi
I study the effect of the galaxies of the Milky Way subgroup on the chemical enrichment of the diffuse gas within the Local Group. The preferred model predicts that the present-day intergalactic medium mass is 1/22 of the initial baryonic mass and its metallicity is 1/20 $Z_\odot$. Nearly 80 % of intergalactic metals were produced in the Galactic bulge.
Downloads: 3
[texts]Carbon and Oxygen Galactic Abundance Gradients: A Comparative Study of Stellar Yields - Leticia Carigi
Chemical evolution models for the Galactic disk under an inside-out formation scenario are presented for seven sets of stellar yields, all of them metal dependent. In particular, the effects of yields from massive and low-and-intermediate-mass stars on the C/O chemical history of the solar neighborhood and on abundance gradients are discussed comparing the predictions with abundance ratios from nearby HII regions, B-stars, dwarf stars, and the Sun...
Downloads: 1
[texts]PN-Carbon Yields and the Chemical Evolution of the Galactic Disk - Leticia Carigi
Two sets of observational carbon stellar yields for low-and-intermediate mass stars are computed based on planetary nebula abundances derived from C II lambda 4267 and C III lambda lambda 1906 + 1909 lines, respectively. These observational yields are assumed in chemical evolution models for the solar vicinity and the Galactic disk. C/O values observed in stars of the solar vicinity and Galactic H II regions are compared with those predicted by chemical evolution models for the Galaxy...
Downloads: 8
[texts]PN-Carbon Yields and the Chemical Evolution of the Galaxy - Leticia Carigi
Two sets of observational carbon stellar yields for low-and-intermediate mass stars are computed from planetary nebulae abundances derived from C II $\lambda4267$ and C III $\lambda\lambda1906+1909$ lines, respectively. By comparing C/O values observed in stars of the solar vicinity and Galactic HII regions with those predicted by chemical evolution models for the Galaxy, which assume these observational yields, I conclude that the C abundances derived from permitted lines are better than those ...
Downloads: 3
[movies]Hugo Chavez y Leticia Bocaranda - Leticia Bocaranda
Leticia Bocaranda y Hugo Chavez Fria, presidente de Venezuela, bailando
Keywords: Leticia Bocaranda; Hugo Chavez Fria; Venezuela
Downloads: 1,583
[audio]Entrevista con Leticia (Wangyi) - Daniel Méndez / Leticia (Wangyi)
Entrevistas con jóvenes chinos. En esta primera entrega hablamos con Leticia, estudiante de español
Keywords: beijing
Downloads: 148
[texts]Dissipative quantum disordered models - Leticia F. Cugliandolo
This article reviews recent studies of mean-field and one dimensional quantum disordered spin systems coupled to different types of dissipative environments. The main issues discussed are: (i) The real-time dynamics in the glassy phase and how they compare to the behaviour of the same models in their classical limit. (ii) The phase transition separating the ordered -- glassy -- phase from the disordered phase that, for some long-range interactions, is of second order at high temperatures and of ...
Downloads: 1
[texts]Fluctuations and effective temperatures in coarsening - Federico Corberi
We study dynamic fluctuations in non-disordered finite dimensional ferromagnetic systems quenched to the critical point and the low-temperature phase. We investigate the fluctuations of two two-time quantities, called $\chi$ and $C$, the averages of which %$$, $$ yield the self linear response and correlation function. We introduce a restricted average of the $\chi$'s, summing over all configurations with a given value of $C$...
Downloads: 2
[texts]Solar origins: Place and Chemical Composition - Leticia Carigi
We discuss a chemical evolution model with Z-dependent yields that reproduces the O/H, C/H, and C/O gradients of the Galactic disk and the chemical history of the solar vicinity. The model fits the H, He, C, and O abundances derived from recombination lines of the HII region M17 (including the fraction of C and O atoms embedded in dust); the protosolar H, He, C, O, and Fe abundances; and the C/O-O/H, C/Fe-Fe/H, and O/Fe-Fe/H relations derived from stars of the solar vicinity...
Downloads: 1
[texts]HII Regions And the Protosolar Helium, Carbon, and Oxygen Abundances in the Context of Galactic Chemical Evolution - Leticia Carigi
We present chemical evolution models of the Galactic disk with different Z-dependent yields. We find that a moderate mass loss rate for massive stars of solar metallicity produces an excellent fit to the observed C/H and C/O gradients of the Galactic disk. The best model also fits: the H, He, C, and O abundances derived from recombination lines of M17, the protosolar abundances,and the C/O-O/H, C/Fe-Fe/H, and O/Fe-Fe/H relations derived from solar vicinity stars...
Downloads: 2
[texts]The Helium and Heavy Elements Enrichment of the Galactic Disk - Leticia Carigi
We present chemical evolution models for the Galactic disk. We also present a new determination of X, Y, and Z for M17 a Galactic metal-rich Hii region. We compare our models for the Galactic disk with the Galactic Hii regions abundances. The $\Delta Y/\Delta O$ ratio predicted from the galactic chemical evolution model is in very good agreement with the $\Delta Y/\Delta O$ value derived from M17 and the primordial helium abundance, Yp, taking into account the presence of temperature variations ...
Downloads: 1
[texts]Slow nonequilibrium dynamics: parallels between classical and quantum glasses and gently driven systems - Leticia F. Cugliandolo
We review an scenario for the non-equilibrium dynamics of glassy systems that has been motivated by the exact solution of simple models. This approach allows one to set on firmer grounds well-known phenomenological theories. The old ideas of entropy crisis, fictive temperatures, free-volume... have clear definitions within these models. Aging effects in the glass phase are also captured. One of the salient features of the analytic solution, the breakdown of the fluctuation-dissipation relations,...
Downloads: 2
[texts]Heterogeneities and local fluctuations in glassy systems - Leticia F. Cugliandolo
The aim of this report is to review a theoretical approach that has been proposed recently to describe dynamic fluctuations in glassy systems (work in collaboration with H. Castillo, C. Chamon, P. Charbonneau, J. L. Iguain, M. Kennett, D. Reichman and M. Sellitto). Firstly, I summarize some of the main features of the averaged and global non-equilibrium relaxation of glassy systems, weakly sheared viscous liquids and weakly tapped granular matter, and how these results have been successfully rep...
Downloads: 6
[movies]Los movimientos de la tierra - Leticia Becerra Turrubiartes
Mapa mental, contenido Movimientos de la Tierra
Keywords: blog.letty
Downloads: 2
[texts]The effective temperature - Leticia F. Cugliandolo
This review presents the effective temperature notion as defined from the deviations from the equilibrium fluctuation-dissipation theorem in out of equilibrium systems with slow dynamics. The thermodynamic meaning of this quantity is discussed in detail. Analytic, numeric and experimental measurements are surveyed. Open issues are mentioned.
Downloads: 4
[texts]Some Implications of Galactic Abundance Gradients Derived from H II Regions and Planetary Nebulae - Manuel Peimbert
By comparing observed abundance gradients with those predicted by a chemodynamical model of the Galaxy the following results are obtained: there is a defficiency of O/H poor PNe in the solar vicinity which implies that only a fraction of intermediate mass stars produce PNe, a similar result is obtained from the observed abundance distributions of Ne/H, S/H and Ar/H; the age distributions of the stellar progenitors of type II and type III PNe show a substantial overlap, but the average age of the...
Downloads: 1
[texts]Dynamics of glassy systems - Leticia F. Cugliandolo
These lecture notes can be read in two ways. The first two Sections contain a review of the phenomenology of several physical systems with slow nonequilibrium dynamics. In the Conclusions we summarize the scenario derived from the solution to some solvable models (p-spin and the like) that are intimately connected to the mode coupling approach (and similar ones) to super-cooled liquids. At the end we list a number of open problems of great relevance in this context...
Downloads: 2
[texts]Effective temperatures out of equilibrium - Leticia F. Cugliandolo
We describe some interesting effects observed during the evolution of nonequilibrium systems, using domain growth and glassy systems as examples. We breafly discuss the analytical tools that have been recently used to study the dynamics of these systems. We mainly concentrate on one of the results obtained from this study, the violation of the fluctuation-dissipation theorem and we discuss, in particular, its relation to the definition and measurement of effective temperatures out of equilibrium...
Downloads: 2
[texts]Photometric Constraints on Chemical Evolution Models of Irregular Galaxies - Leticia Carigi
Photometric properties of stellar populations that evolve according to chemical evolution models developed by Carigi, Colin, & Peimbert (1999) and Carigi & Peimbert (2001) are explored. Models explain the oxygen abundance and gas mass fraction of irregular galaxies NGC 1560, I Zw 18, NGC 2366, and a typical irregular galaxy. The photometric predictions help to narrow down the range of possible chemical evolution models...
Downloads: 10
[audio]Mesa de tres patas - María Leticia
Trabajo Práctico Producción Radiofónica
Keywords: Mesa de Tres Patas - Fontanarrosa
Downloads: 7
[texts]cmd - nuria leticia mtz gallardo
ejercicio de clase
Keywords: material; clase; ejercicio; práctica
Downloads: 3
[texts]Statistica Mechanics - Leticia F. Cugliandolo
Contents: Introduction; Phase Transitions; Disorder; Stochastic processes; Surfaces and interfaces. Lecture Notes Collection FreeScience.info ID2313 Obtained from http://www.phys.ens.fr/~leticia/TEACHING/cours-orsay.pdf http://www.freescience.info/go.php?pagename=books&id=2313
Keywords: Statistical Mechanics
Downloads: 13
[texts]Quantum TAP equations - Giulio Biroli
We derive Thouless-Anderson-Palmer (TAP) equations for quantum disordered systems. We apply them to the study of the paramagnetic and glassy phases in the quantum version of the spherical p spin-glass model. We generalize several useful quantities (complexity, threshold level, etc.) and various ideas (configurational entropy crisis, etc), that have been developed within the classical TAP approach, to quantum systems...
Downloads: 1
[texts]Thermal properties of slow dynamics - Leticia F. Cugliandolo
The limit of small entropy production is reached in relaxing systems long after preparation, and in stationary driven systems in the limit of small driving power. Surprisingly, for extended systems this limit is not in general the Gibbs-Boltzmann distribution, or a small departure from it. Interesting cases in which it is not are glasses, phase-separation, and certain driven complex fluids. We describe a scenario with several coexisting temperatures acting on different timescales, and partial eq...
Downloads: 1
[texts]A scenario for the dynamics in the small intropy production limit - Leticia F. Cugliandolo
We present a scenario for the nonequilibrium dynamics in the limit of small entropy production. We discuss (i) the appearence of different time-scales, (ii) the modification of the fluctuation-dissipation theorem and its relation to effective temperatures and partial equilibrations and (iii) the validity of Onsager reciprocity relations. We distinguish these properties by their reaction to infinitesimal perturbations...
Downloads: 2
[texts]Effective temperature of a dissipative driven mesoscopic system - Liliana Arrachea
We study the nonequilibrium dynamics of a mesoscopic metallic ring threaded by a time-dependent magnetic field and coupled to an electronic reservoir. We analyze the relation between the (non-stationary) real-time Keldysh and retarded Green functions and we find that, in the linear response regime with weak heat transfer to the environment, an effective temperature accounts for the modification of the equilibrium fluctuation-dissipation relation...
Downloads: 2
[texts]Cluster expansions in dilute systems: applications to satisfiability problems and spin glasses - Guilhem Semerjian
We develop a systematic cluster expansion for dilute systems in the highly dilute phase. We first apply it to the calculation of the entropy of the K-satisfiability problem in the satisfiable phase. We derive a series expansion in the control parameter, the average connectivity, that is identical to the one obtained by using the replica approach with a replica symmetric ({\sc rs}) {\it Ansatz}, when the order parameter is calculated via a perturbative expansion in the control parameter...
Downloads: 1
[texts]Dynamics of dilute disordered models: a solvable case - Guilhem Semerjian
We study the dynamics of a dilute spherical model with two body interactions and random exchanges. We analyze the Langevin equations and we introduce a functional variational method to study generic dilute disordered models. A crossover temperature replaces the dynamic transition of the fully-connected limit. There are two asymptotic regimes, one determined by the central band of the spectral density of the interactions and a slower one determined by localized configurations on sites with high c...
Downloads: 2
[audio]Recuerdo a Romina Yan - Leticia Ditrani y Anahí Sanabria
Keywords: Material audiocreativa
Downloads: 2
[texts]Defects dynamics following thermal quenches in square spin-ice - Demian Levis
We present a study of the single spin flip stochastic dynamics of the two dimensional sixteen vertex model. We single out several dynamic regimes controlled by different processes that we describe. We analyse the emergence of very long-lived metastable states and their dependence on the system size, boundary conditions, and working parameters. We investigate the coarsening process after quenches into the ordered ferromagnetic and antiferromagnetic phases...
Downloads: 10
[texts]Mean-field theory of temperature cycling experiments in spin-glasses - Leticia F. Cugliandolo
We study analytically the effect of temperature cyclings in mean-field spin-glasses. In accordance with real experiments, we obtain a strong reinitialization of the dynamics on decreasing the temperature combined with memory effects when the original high temperature is restored. The same calculation applied to mean-field models of structural glasses shows no such reinitialization, again in accordance with experiments...
[texts]Out of equilibrium dynamics in the bidimensional spin-ice model - Demian Levis
We study the dynamics of 2d spin-ice following a quench from a fully disordered initial condition (equilibrium at infinite temperature) into its disordered, ferromagnetic and antiferromagnetic phases. We analyze the evolution of the density of topological defects and we show that these take finite density over very long periods of time in all kinds of quenches. We identify the leading mechanisms for the growth of domains in the ordered phases and we evaluate the (anisotropically) growing lengths...
Downloads: 4
[texts]Dynamic fluctuations in unfrustrated systems: random walks, scalar fields and the Kosterlitz-Thouless phase - Federico Corberi
We study analytically the distribution of fluctuations of the quantities whose average yield the usual two-point correlation and linear response functions in three unfrustrated models: the random walk, the $d$ dimensional scalar field and the 2d XY model. In particular we consider the time dependence of ratios between composite operators formed with these fluctuating quantities which generalize the largely studied fluctuation-dissipation ratio, allowing us to discuss the relevance of the effecti...
Downloads: 3
[texts]Fluctuations in glassy systems - Claudio Chamon
We summarize a theoretical framework based on global time-reparametrization invariance that explains the origin of dynamic fluctuations in glassy systems. We introduce the main ideas without getting into much technical details. We describe a number of consequences arising from this scenario that can be tested numerically and experimentally distinguishing those that can also be explained by other mechanisms from the ones that we believe, are special to our proposal...
Downloads: 1
[texts]Quench dynamics of the 2d XY model - Asja Jelic
We investigate the out of equilibrium dynamics of the two-dimensional XY model when cooled across the Berezinskii-Kosterlitz-Thouless (BKT) phase transition using different protocols. We focus on the evolution of the growing correlation length and the density of topological defects (vortices). By using Monte Carlo simulations we first determine the time and temperature dependence of the growing correlation length after an infinitely rapid quench from above the transition temperature to the quasi...
Downloads: 9
[texts]The entrance dynamics of polymers into a gel - Walter Kob
We use computer simulations to study the (driven) dynamics of a charged polymer in a disordered medium, thus mimicking the setting used in gel electrophoresis. In agreement with experiments, we find that inside the gel the mobility of the polymer is only a weak function of its length N. In contrast to this, the mean entrance time into the gel, is a very strong function of N, \propto N^1.3, and does not show any sign of saturation with increasing N...
Downloads: 1
[texts]Slow relaxations and history dependence of the transport properties of layered superconductors - Raphael Exartier
We study numerically the time evolution of the transport properties of layered superconductors after different preparations. We show that, in accordance with recent experiments in BSCCO performed in the second peak region of the phase diagram (Portier et al, 2001), the relaxation strongly depends on the initial conditions and is extremely slow. We investigate the dependence on the pinning center density and the perturbation applied...
Downloads: 2
[texts]Effective potential renormalization and polaronic mass shift in a trapped dynamical impurity-luttinger liquid system - Julius Bonart
Recent experiments with cold atoms on the impurity motion in one-dimensional liquids of interacting bosons have revealed an interesting interplay between the polaronic impurity mass shift and the renormalization of the optical potential. We show that the influence of the external trap on the Bose gas leads to a steeper effective potential for the impurity. We propose a framework in which this potential renormalization and the mass shift can be quantitatively understood by combining a semi-classi...
Downloads: 3
[texts]Infinitesimal deformations of a Calabi-Yau hypersurface of the moduli space of stable vector bundles over a curve - Indranil Biswas
Let $X$ be a compact connected Riemann surface of genus $g$, with $g\geq 2$, and ${\cal M}_{\xi}$ a smooth moduli space of fixed determinant semistable vector bundles of rank $n$, with $n\geq 2$, over $X$. Take a smooth anticanonical divisor $D$ on ${\cal M}_{\xi}$. So $D$ is a Calabi-Yau variety. We compute the number of moduli of $D$, namely $\dim H^1(D, T_D)$, to be $3g-4 + \dim H^0({\cal M}_{\xi}, K^{-1}_{{\cal M}_{\xi}})$...
Downloads: 4
[texts]Sparse random matrices: the eigenvalue spectrum revisited - Guilhem Semerjian
We revisit the derivation of the density of states of sparse random matrices. We derive a recursion relation that allows one to compute the spectrum of the matrix of incidence for finite trees that determines completely the low concentration limit. Using the iterative scheme introduced by Biroli and Monasson [J. Phys. A 32, L255 (1999)] we find an approximate expression for the density of states expected to hold exactly in the opposite limit of large but finite concentration...
Downloads: 2
[texts]Aging and effective temperatures in the low temperature mode-coupling equations - Leticia F. Cugliandolo
The low-temperature generalization of the mode-coupling equations corresponds to the dynamics of mean-field disordered models in the glassy phase. The system never achieves equilibrium, preserving the memory of the time elapsed after the quench throughout its evolution. A concept of effective temperature can be made quite rigorous in this context by considering readings of thermometers in different time-scales and the thermalization of weakly coupled subsystems.
Downloads: 2
[texts]Restriction of the Poincaré bundle to a Calabi-Yau hypersurface - Indranil Biswas
Let $\cMx$ be the moduli space of stable vector bundles of rank $n\geq 3$ and determinant $\xi$ over a connected Riemann surface $X$, with $n$ and $d(\xi)$ coprime. Let $D$ be a Calabi-Yau hypersurface of $\cMx$. Denote by $U_D$ the restriction of the universal bundle to $X\times D$. It is shown that the restriction $(U_D)_x$ to $x\times D$ is stable, for any $x\in X$. Furthermore, for a general curve the connected component of the moduli space of semistable sheaves over $D$, containing $(U_D)_x...
Downloads: 20
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